Warming is changing bird migration patterns

Climate change is radically reshuffling UK bird species, report finds

New migrants are arriving while rising temperatures drive others away, and egg laying is taking place earlier in the year

The Guardian (U.K.), Dec. 5, 2017

Climate change is radically reshuffling Britain’s birds, with some species disappearing while new migrants are settling. Timings are being reset too, with egg laying getting earlier in the year, while autumn departures for warmer climes are delayed by up to a month.

The State of the UK’s Birds report for 2017 published on Tuesday, reveals the profound impact of global warming on Britain’s bird life, which is set to become even greater in the future.

Average temperatures in the UK have increased by almost 1C in recent decades and familiar birds like swallows, which migrate to Africa every autumn, have responded by leaving up to four weeks later. Others, such as garden warblers and whitethroats, are also enjoying warmer British weather for longer.

The migratory birds are also arriving and breeding earlier in the spring than in the 1960s. The great tit is a fulltime resident but it is also laying its eggs 11 days earlier than 40 years ago.

The UK’s increasingly warmer and wetter winters have induced some short-distance migratory birds to give up their journeys entirely and remain in the UK. The breeding numbers of blackcaps and chiffchaffs have both more than doubled since 1970.

However, the warmer conditions are posing a serious risk of extinction in the UK for many of the nation’s rarer birds, particularly those found in the north. Among these the dotterel, whimbrel and common scoter have already seen significant population declines.

But while cold-adapted birds suffer, those preferring warmth are taking advantage. Those currently limited to southernmost regions, such as the quail, little egret and hobby, have increased their numbers. Ornithologists expect other species, including the little bittern and zitting cisticola, may colonise the south in coming years as they escape the rising heat in continental Europe.

The State of the UK’s Birds report is produced by the RSPB, British Trust for Ornithology and the Wildfowl & Wetlands Trust, together with the UK’s statutory nature conservation bodies including Natural England. Michael Morecroft, at Natural England, said:

“Climate change is undoubtedly going to be one of the greatest influences, both positive and negative, on the future status of birds and other biodiversity in England and the UK.”

Morecroft said it was therefore vital that wildlife habitats are both expanded and better protected to help species better survive extreme weather and help them spread to newly suitable areas.

The RSPB’s Daniel Hayhow, the lead author of the report, said: “For some species climate change will provide opportunities to increase and expand provided the right habitat is there, while others will be vulnerable, increasing their risk of extinction as breeding species in the UK.”